Because of the problems discussed above, it is common for installers to set the cut-out pressure setting too low and cause the product compartment to operate at temperatures colder than necessary, just to prevent excessive compressor cycling from occurring. These problems also cause systems to be installed and set to operate at condensing pressures that call for temperatures much warmer than the ambient conditions would ordinarilyallow. However, increasing the capacity of the system resulting from the reduced condensing pressures will significantly alter the required cut-out pressure settings and require frequent readjustment of the low pressure control.
Patents which are typical of prior art for mechanically or electromechanically controlling the operation of compressors in a refrigeration or cooling system include the following U.S. Pat. Nos: 3,885,938; 3,828,152; 3,719,057; 3,581,519; 3,580,006; 3,552,137; 3,513,662; and 3,377,816. However, all of the baove patents are directed to either parallel or cascaded multiple compressor systems.